Django笔记

class Diabetes(BaseModel):
    user = models.ForeignKey(User, on_delete=models.SET_NULL, blank=True, null=True)
    pregnancies = models.IntegerField(blank=True, null=True, verbose_name='怀孕次数')
    glucose = models.IntegerField(blank=True, null=True, verbose_name='葡萄糖')
    blood_pressure = models.IntegerField(blank=True, null=True, verbose_name='血压')
    skin_thickness = models.IntegerField(blank=True, null=True, verbose_name='皮肤厚度')
    insulin = models.DecimalField(max_digits=4, decimal_places=1, blank=True, null=True, verbose_name='胰岛素')
    bmi = models.DecimalField(max_digits=4, decimal_places=2, blank=True, null=True, verbose_name='身体质量指数')
    pedigree_function = models.DecimalField(max_digits=4, decimal_places=3, blank=True, null=True, verbose_name='遗传特性')
    age = models.IntegerField(blank=True, null=True, verbose_name='年龄')
    outcome = models.IntegerField(blank=True, null=True, verbose_name='预测结果,0正常/1发病')
    result = models.DecimalField(max_digits=5, decimal_places=4, blank=True, null=True, verbose_name='预测患病概率')
    
    class Meta:
        db_table = 'diabetes'
        verbose_name = '糖尿病数据'
        verbose_name_plural = verbose_name

    
class User(AbstractUser):
    sexType = (('M', 'male'), ('F', 'Female'))
    roles = models.IntegerField(default=1, verbose_name='角色')
    code = models.CharField(max_length=256, null=True,blank=True, verbose_name='邮箱验证码')
    c_time = models.DateTimeField(auto_now_add=True, verbose_name='注册提交时间')
    is_remember = models.BooleanField(default=False, verbose_name='是否记住登录状态')
    sex = models.CharField(max_length=1, choices=sexType, null=True, blank=True)

# 1.使用annotate和F重命名字段
user = User.objects.annotate(userName=F('username'), pregnancies_count=Count('diabetes'))

# 2.查询每个用户有多少条Diabetes记录
user = User.objects.annotate(pregnancies_count=Count('diabetes'))
print(user.values('pregnancies_count'))

# 3.外键反向查询：查询用户为song的所有diabetes数据
user = User.objects.filter(is_active=True, username='song').first()
user.diabetes_set.all()  # 或者通过related_name查询：user.related_name.all()

# 4.查询Diabetes表中所有用户为song的记录
# 表名小写__字段名，或者related_name__字段名
diabetes = Diabetes.objects.filter(is_active=True, user__username='song').values()

# 5.查询diabetes表中age=21的对应的所有user记录，queryset有重复可以使用distinct去重
user = User.objects.filter(is_active=True, diabetes__age=21).values().distinct()


# 6.统计胰岛素含量的最高值和平均值之差
Diabetes.objects.filter(is_active=True).aggregate(insulin_diff=Max('insulin')-Avg('insulin')).values()